Charge forming device for internal-combustion engines



Sept. 3, 1929. F. E. ASELTINE 1,727,255

CHARGE FORMING DEVICE FOR INTERNAL COMBUSTION ENGINES s Sheet-Sheet 1 Filed Jan. 26, 1926 Sept. 3, 1929. F. E. ASELTINE CHARGE FQRIING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Jan. 26, 1926 3 Sheets-Sheet 2 Sept. 3, 1929.

F. E. ASELTINE 1,727,266

CHARGE FORMING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Jan. 26, 1926 {Sheets-Sheet 5 m N Q1 k K g Q g b v "3 I o l "n N a N m 0 N v Patented Sept. 3, 1929.

UNITED STATES PATENT OFFICE.

FRED n. ASELTINE, or DAYTON, OHIO, ASSIGNOR, BY mnsnn nssremmms, 'ro DELCO- 1 am conroan'non, or DAYTON, onro; A oonrona'rron on DELAWARE.

cannon ronmnve nnvron ron INTERNAL-COMBUSTIONENGINES.

Application filed January 26, 1926; Serial No. 83,979.

This invention relates to charge forming devices for internal combustion engines, especially automotive vehicle engines.

This invention provides various improvemerits and changes over the devices of my prior applications, Serial N 0. 4,665, filed J anuary 26, 1925 and Serial No. 54,592, filed September 5, 1925.

An important feature of the present inven- 10 tion is the adjustable liquid dash pot for stabilizing and modifying the action of the suction-opened main air inlet valve.

Anotherlfeature of this invention is the improved form of primary carburetors, each 15 having a single individualfuel jet, the fuel flow to all of said jets being controlled by a suction actuated gravity valve.

Another feature of this invention is the one-way valve placed in the fuel duct leadin 2 to the primary carburetors to prevent bac flow of fuel from said carburetors.

Another feature is the depression equalizing duct interconnecting the outlets of the primary carburetors whereby th'vsame engine 2 suction is always applied to each of said pri-' mary carburetors.

Another feature is the improved design of air and fuel jets for the primary carbure tors for delivering a more uniform rich fuel 30 mixture.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a referred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of a charge forming device fora six cylinder internal combustion 40 engine, built according to this invention.

Fig. 2 is a section on line 22 of Fig. 1.

Fig; 3 is a view showing part of the manifold in side elevationbut the central portion in vertical section, said section being 45 taken on line 3-3 of Fig. 4.

Fig. 4 is a horizontal section taken on line 4-4 of Fig. 3.

Fig. 5 is a vertical section taken on lines 55 of Figs. 4 and 7.

00 Fig. 6 is a side elevation of the central portion of the device but having parts broken away to show certain interior construction;

Fig. 7 is a plan view. of the distributing block, showing the equalizing duct-interconnecting the outlets of the'prirnary carburetors in dotted lines.

F g.6 is a section on line 88 of Fig. 7.

Similar reference characters refer to sim- 1lar parts throu bout the several views.

Numeral 10 esignates in its entirety the air mamfold provided with the three branches 11,12 and 13, each of which branches connects to an engine intake port which serves the two adjacent cylinders. Fig. 2 shows only one engine intake valve of the pair of similar valv served by the branched intake passa e 14 a d intake port 16 in the cylinder bloc casting.

The air manifold 10 has a main air inlet elbow 17 bolted theretoby bolts 18. The conical main air valve 20 seats upon the lower end of elbow 17. A casting 21 of a general circular form is bolted by bolts 23 to the under side of manifold casting 10 (see Fig. 3). Fixedly mounted in casting 21 is the casting 22 which serves .as a vertical guide for the air valve stem 24 and for the dash pot cylinder 25. The dash pot piston 26 is pinned to the lower end of valve stem 24by pin 27 (see Fig. 5) in such a manner that there is a slight universal movement of the piston26 on the stem 24.. This permits the conical air valve 20 to be selfcentering to a certain extent since the ide bearing in casting 22 is made sutficiently oose to permit this. The air valve 20 is held urged to its seat by the coil spring 28 whose upper end seats upon the seat cup 29 suitably attached to stem 24, and whose'lower end seats upon the seat cup 30 which is vertically slidable within the cylindrical portion 31 of casting 22. This seat cup 30 may be raised or lowered by a manually operated bifurcated lever 32 which is provided with diametricall opposed lugs 33, each of which rides wit in a slot 34 in the seat cup 30 (see Figs. 4, 5 and 6). The stationary cylindrical portion 31 is provided with slots 34 of suflicient width to permit the arcuate movement of the lugs 33 extending therethrough. The short shaft 36 UPOII'WhICh lever 32 is mounted has a bearing in the casting 21 and its projecting end has a. lever arm 37 which is connected through suitable actuating linkage (not shown) toacontrol located adjacent the drivers seat. It is thus seenthat the driver may manually adjust the tension of spring 28 at will and thus vary the force which urges the air valve 20 to closed position.

As the air valve 20 is opened by the depression in the manifold '10 the dash pot piston 26 moves down in the cylinder 25 and so (lamps the opening movementand prevents fluttering of said air valve. Piston 26 has one .or more small holes 40 therein which are closed by the disk check valve 41 upon downward movement of the piston but which open upon upward movement thereof. Hence air valve 20 opens slowly according to the leakage past piston 26 but closes relatively quickly due to the opening of check valve 41.

Dash pot cylinder 25 has a by-pass 42 in t a8 wall thereof (see Fig. 3), the upper port 4 of which being located a short distance below the upper edge of piston 26 when air valve 20 is on its seat. Upon downward movement of piston 26 the liquid fuel in the dash pot cylinder leaks past piston 26 around its entire periphery but chiefly passes through by-pass 42 and leaks past the shorter'lengt'h of the piston between port 43 and the upper edge thereof. As the piston travels down this leakage through by-pass 42 progressively increases until the. top edge of piston 26 clears port 43.

whereupon there is a sudden decrease in the force resisting the opening movement of air valve 20. The distance between the top edge of piston 26 and port 43 of by-pass 42 when valve 20 is upon its seat may be adjusted to suit requirements by raising or lowering the dash pot cylinder 25, as follows: The lower end of cylinder 25 is rigidly attached to an offset vertical rod 50 whose upper threaded end 51 extends through a hole in casting 21. gear nut 52 is suitably housed in a recess in casting 21 (see Fig. 3 and is threaded upon the threaded end 51 0 rod 50. This gear nut 52 is rotated by the spiral gear. 53 on the horizontal shaft- 54 which projects laterally outward from casting 21 and has a knurled knob 55 thereon. It will now be clear that by rotating knob 55 the gear nut 52 may be turned in either direction and hence the cylinder 25 will be raised or lowered as desired. Preferably a light coil compression spring 56'is provided having its lower end engaging a collar 57 on rod 50 whereby the cylinder 25 is held urged downward at all times, thus'avoiding any looseness.

Liquid fuel is maintained at a constant level in the float bowl 60. Fuel enters at the pipe connection 61 and passes down through the valve 62 which is actuated by the float 63 in the well known manner to maintain a constant' fuel level. Liquid fuel has free access to the dash pot cylinder above the piston 26 throu h the slots 35 and thus the dash pot cylin er remains-filled at all times.

The primary carbureting devices will now be described. The manifold casting 10 is provided adjacent its central branch 12 with an integral projection 70. This projection has a vertical duct 71 therein located vertically above the float bowl 60. An extension duct 72 interconnects with projection 70 and extends the duct 71 down below-the fuel level in bowl 60 (see Fi 5). The projection 70 is provided with a at upper surface or table 73 upon which the distributing block 74 is fixed by means of two screws 7 5. This block 74 has. three parallel drilled passages 7 6, 77 and 78 therein which constitute the fuel and air mixing passages of the three rimary carburetors. The lower surface of lock 74 has a liquid fuel distributing canal 80 therein, which canal registers with the vertical duct 71 leading fuel up from the float bowl. A removable fuel metering jet 81 leads fuel from canal 80 into each of the passages 7 6, 77 and 78. An air inlet bushing 82 admits air to each of passages 76, 77 ,78 adjacent the fuel jets 81. The inner end of bushing 82 has a projection 83 of slightly reduced diameter which projects above the fuel jet 81 as clearly shown in Fig. 8. The upper part of the projection 83 is cut away on a bias as shown. It has been foundthat this arrangement of air and fuel jets provides a very uniform fuel mixture even though the proportion of fuel to air is large compared to that delivered by ordinary carburetors. This overrich fuel mixture suppliedby the primary carburetors 7 6, 77, 78 is 'led individually to the three branches'll, 12,

13 of the air manifold 10.

The branch 13 has a large venturi'90 held therein by the tapered set screw 91 (see Fig. 2). Venturi 90 has a hole 92 on its upper side adjacent the restricted throat which registers with the hol e93 in the branch 13. A rich mixture duct. .94 conveys the fuel mixture from the primary carburetor 78 to the hole 93 in 'branch 13. Air entering the venturi 90 from the main air inlet valve 20 mixes with overrich fuel mixture delivered through hole 92 to form a proper fuel mixture for the engine. The branches 11 and 12 are also rovided with venturis90 similar to branch 1. branch 11 being supplied by primary carburetor 76 through a rich mixture duct 94. while the central branch 12 is supplied directly by the passage 77 in the distributor block 74 (see Fig. 8). The manual throttles 95 in each branch have individualthrottle shafts 96 which are interconnected by suitable universal joints 97 which permit expansion of the throttle shafts and render exact alignment of all three shafts unnecessary. All three throttles 95 are actuated by the lever arm 98 fixed to the central shaft 96. Arm 98 is actuated by a suitable control (not shown) located adjacent the drivers seat in a well known manner.

At small openings of throttles 95,. that is,

when only small charges are passing through moving. To avoid such a. tendency each branch is provided with automatic passage restricting valves which open according to the blast of the entering charge and thus always cause the fuel mixture to enter the en-} gine ports 16 at high velocity. Each branch 2. Each tube 100 has a transverse hinge pin 102 upon which two flapper valves 103 are pivoted. These valves 101-3 are urged to closed position by the springlOi which is connected to valves 103 in the manner clcarlv illus-' trated. The crescent-shaped opening 105 between tube 100 and the inner wallsof the branch provides an unrestricted fuel charge passage for idling.

A depression equalizing duct 10d interconnects all three branches at a point on the engine side of the manual throttles 95. In normal operation, the engine maintains a. depression in the air manifold 10 due to the spring closed main air valve 2(l.-, This depression acting through the ducts 94f draws primary air through the bushings 8:2"and'lid uid fuel up fromfthe fioat bowl through ducts72 and 71 to canal and thence through the three fuel jets 81 into the primary air stream vforming an overrich mixture in each primary carburetor This richinixture. is drawn through the holes 92 and delivered into the main air blast through the venturis in each branch, thus forming a correct mixture for the engine. The vertical duct 71 is provided with a tapered gravityvalve 110 which/has an aperture 111 extending therethrough. 'At idling speeds sufiieient fuel is ordinarily supplied through the hole 111 to supply the proper mixture;v As the engine speed is increased the increa'sed suction-on the fuel 'jets 81 canses the valve 110 to be corre spondingly lifted fron its seat to permit-a greater, fuel flowto said jets; It is thus seen thativalve 110 constitutes an automatic fuel n eteringval-ve for regulating' the' fuel flow to the primary carburetors. Locatednabovethe gravity valve 110 is a check valve {112 :wl'iich per nitsfuel to v flow upward but which prevents any-downwardflowof'fuel. has been found that under Feertain conditions, for instance when the" engine speed: suddenly reduced from i I o" low'spee l-,;tlie sudden rediu tion tion on the.vertical'colnmn of fuel Land permits'this column to p s. fliciently to cause a temporary fuel 'msdropping under such conditions and so enable the engine to idle properly immediately upon a sudden} elosin'g of the throttles 95.

It has been found that the three carburetor passages 76, 7 7 7 8 are not alwa s subjected to the same degree of suction,pro ably due to the different lengths and'shapes of the rich-mixture due-ts leadingfrom the primary carburetors to the vent-uris 90 In order to equalize the depression applied to all three primarycarburetors and soobtain .u'ni

form rich mixtures therefrom ill-depression egualizingduc't 11 5 .is provided interconnectmg the three passages 76, 77, 78 at a point adjacent the air and fuel jets. Thedi'stributor block 74 has three apertures 116 extend ing down into the three passages 76, 77, 78 in the same location relative to the air and fuel jets therein. The duct- 115;in the separate block 117 is-of such shape as to register with all three aperturesillG. The block 117 is suitably secured to the top of block 74 by two screwsllS. (See'lligsi75121111158.)-

- The operation of the device for accelerating the engineisjfas follows: Consider the; engine idling with the throttles in nearly closed position. Under thiscondition theair valve 20 will be open only a very'smallainount s nce tlieire'wi'll be only a small depression in rhea-tie, manifold 10. upkv the-throttles 95;

be suddenly'jopeiie'd -the depression in'mani told 10 will he suddenly increased. The dash pot pist'on 26 however" will'prevent air valve 20 from opening rapidly and hence this lin creased depression will actfirst on the primary carburetors 76, 77 7 8 to provide a richer mixture for accelerating purposes. damping effect of piston 26 decreases progres sively as air valve 20' opens due tofby-pass port 43 approaching beinguncovered bythe The l downward movement ofpiston 26. Assoon as port 43 is uncovered the damping effect is greatly decreased whereupon fvalve .20 opens rapidly to supply sufficient air to the engine to' give the desired increased power. It will be clear'therefore that fthe' distance p'or't43 lies below. the upper edge .bfpistiin 26 when air valve 20 is closed determines the period of highdamping of valve 20, Thislperiod may be varied by adlusting the vertical-position of cylinder 25 as described above to givi g the bestaccelerating effect according to the temp u ethe ng ne, or any othe operatin conditions. If klesire(l,tlie 'qunar 25 may be arranged to he molved'by'athermostatic d v n's'te d 0f man ally l ewo in" h drawings and described inidet-ailhereim' \iVhile'. the form of embodiment-oi: thepresent invention as 'l1erein disclosed. 0 titutes a preferred form; it is tofhe'understom that other forms mightbe' adopted. allicoining within thescope of the claims which follow. hat is claimed is as follows: Lin :1 charge foi-n ing-( levic e for a multicylinder internal cbmbust'ion engine hayinga duct for leading "liquid vfuel to-all of said plurality of intake ports, an individual primary carburetor for supplying a fuel mixture to .each intake port, each primary carburetor having a single fuel jet, a common du'ctfor leading liquid fuel to all of said jets, and

a suction actuated fuel metering valve in said duct. 2. In'a charge forming device for a multicylinder internal combustion engine having a plurality of intake ports, an individualpr mary carburetor for supplying a fuel mixture to each intake port, each primaryc'arburetor havinga single fuel jet, a common 'duct for leading liquid fuel toall of said jets, and a gravity valve in said duct for metering the fuel flovs to all of said jets.

3. In a charge forming device for a multicylinderainternal combustion engine-having a plurality ofintake ports, an individual primary carburetor for supplying a fuel mixture to each intake port, each primary carburetor having a single fuel jet, a common duct for leading liquid fuel to all of said jets, and

a two stage suctionoperated valve in said .liquid fuel duct for regulating the flow of fuel to said jets, i u 4. In a charge cylinder internal combustion engine having a plurality of 'intake ports, an individual primary carburetor for supplying a fuel m1x-. ture to each intake port, each primary carburetor having a single fuel jet, a common jets, and a suction actuated fuel regulating valve in said duct, and a one-way valve in said duct permitting fuel to flow only toward said 'ets. I I

5. n a charge forming device for a multicylinder internal combustion engine having a plurality of intake ports, an individual primary carburetor for supplying a fuel mixture to each intake port comprising a mixture passage having fuel and airinlets, and a depression equalizingduc't interconnecting the mixture passages of said primary carburetors for equalizing the engine suctionthereon.

6. In a charge formingdevice for a multicyclinder internal combustion engine having a plurality of intake ports, an individual prunary carburetor for'supplying a fuel mixture to each intake port comprising a mixture passage having fuel and air inlets, said primary carburetors beingpositioned relatively close together, and a short depression equalizing duct interconnecting said mixture passages.

7. In a charge forming device for a multicylinder internal combustion engine having a plurality of intake'ports, a main air mani fold having a branch lcadingto each intake port, an individual primary carburetor for supplying an overrich fuel mixture to each of said branches comprising a mixture'passage having fuel and air inlets, said .primary forming device for a multi-' said bushing having a projection on its inner end extending over but spaced from said fuel j 9. In a charge forming device for an internal combustion engine having a plurality of intake ports, an air manifold having a branch for each intake port and-a common main air inlet, an engine suction controlled air valve in said inlet, a dash pot for .damping theopening of said air valve, said dash pot comprising a piston connected to said air valve, a'cylinder having a by-pass .port opened and closed by said. piston for decreasing the damping effect upon said air valve in its more open positions, and means for changing'the position of said cylinder to vary the time of opening'of said by-pass port by said'pis'ton.

10. In a charge formm device for-an internal combustion engine, main air inlet, a

spring closed air valve insaid inlet-opened by the engine suction,-a dash pot-for modifying the action of said air valve, said dash pot comprising a piston and cylinder, a by-pass duct in said cylinder for decreasing thedamping effect upon said air valve in certainposltions, and means for adjusting the position of 5 said cylinder for varying the effective action of said by-pass duct.

11. A charge formingdevicefor aninternal combustion engine having in combination a mixture passage, a fuel jet for delivering fuel to said passage, anair inlet bushing for 1 admitting air to said passage, said bushing having a projection on its inner end extending over but spacedfrom the fuel jet to pre vent the incoming air contacting directly with the fuel jet.

12. In a charge forming device .for a multicylinder internal combustion engine having a plurality of intake ports, an individual primary carburetor for sup'plying'afuel mix-,-

forming device for a multi-- ture to each intake port, said primary carbu;

retors each comprising amixture passage having an air inlet bushing thereimand'. a. fuel jet entering said passage adjacent the inner end of said bushing, said b'ushing.-having a projection on its inner end extendlngo'ver but spaced from said fuel 'et, I

13. A charge forming. evlce for an iiit'er nal combustion en'gme having in combination a mixing chamber, a fuel inlet therefor, a the air valve, and means for varying the o nmainair inlet, a suction operated spring coning movement of the air valve before sai retrolled valve therein, means for retarding the tarding means is rendered inefiective. 1 opening of said valve on opening of the throt- In testimony whereof I hereto afiix my sigtle to enrich the mixture for acceleration, nature. means for rendering the retarding means inefiective after a predetermined movement of FRED E. ASELTINE. 

